MACCLENNY, Fla -- They gathered in the sanctuary of Christian Fellowship Temple: parents and children, teachers and students, doctors and nurses.

It was Jan. 12. They were there to pray and sing together, to celebrate the life of Alex Colbert, who died the week before, after a 20-year fight with cystic fibrosis.

Colbert used his lifelong battle to spread an important message: Never give up and always keep fighting.

Born on Aug. 19, 1989 in Ft. Lauderdale, he was diagnosed with CF in infancy. The terminal, genetic disease causes mucus to build up in the body's organs and shut them down. Patients with CF have trouble digesting food as well as trouble breathing.

There is no cure, only daily treatments of medicine. Most CF patients do not live past their 30s.

Dawn and Bob Colbert's third son was always different, and not because of his disease.

Growing up in Baker County, Alex Colbert never lagged behind his older twin brothers, Brandon and Ryan. He was always right in the middle of the fun at their church youth group, or just hanging out in the neighborhood with his brothers, climbing trees.

Above all, Colbert's family remembers the boy's sensitivity toward others, and his wry smile and laugh. "He'd go out of his way to make sure people were happy," Ryan Colbert recalled.

But Colbert's health could fall into a tailspin at any time. He was in and out of Wolfson Children's Hospital - healthy one day, and gravely ill the next.

"He was always a funny person. That's the best way I could describe him. He was always able to take something bad and put humor into it," his father said.

Despite juggling two full-time jobs and raising three boys, Bob and Dawn Colbert said taking care of Alex was easy - in part, because Alex was so good at taking care of himself.

The Colberts said there were many occasions where Alex was so sick, they didn't know if he would make it through the night. They'd call all his friends to the hospital to say goodbye, and then the next morning, Alex would spring back.

Early December brought one of those nights when the Colbert's weren't sure how much longer Alex could hold on.

"He knew that it was non-curable. But he didn't want anybody to give up either. He wanted to continue to push forward. Stay as healthy as he could and keep fighting," Dawn Colbert said.

From his hospital bed in pediatric intensive care at Wolfson Children's, Alex shared his story. He wanted people to remember him for his fight to live.

And Alex fought through music. At 15, he learned to play the guitar, after watching his brother play.

"It became second nature to him. Even if he was sick, every day he picked up that guitar and played it," Ryan Colbert said.

Both of Alex's brothers are musical, and so it was no surprise when their brother added singing and songwriting to his talents.

He wrote about his emotions: the happiness his friends and family brought him, the loneliness he felt in the hospital, and the pain and courage of fighting cystic fibrosis.

"Music helps me express my feelings," said Colbert, from the hospital last December.

He described his favorite kind of music as, "laid-back acoustic guitar," citing musicians like Jason Mraz and John Mayer.

Music producer Tim Nold spent a lot of time writing, recording and editing with Alex, who wrote seven songs. His anthem is called, "65 Roses."

"I wrote it because of a story about a kid who couldn't pronounce 'cystic fibrosis,' so he said, '65 roses,'" Alex explained.

When he used to sing it, the song was full of hope and sadness. The lyrics: "Just give me one more day/just give me one more night/to say goodbye to life."

"Just giving the patient one more chance to feel better. Not letting disease take over," Colbert said.

He had a clear picture of who he was and how he wanted to be remembered. "How much of a fighter I am. That if I could go this long with this disease, then [everyone else] could do it. That they could fight their fight," he said.

Alex fought his way out of the hospital and back home one more time. He passed away at his home, surrounded by friends and family on January 7, 2010.

"I find comfort in knowing where he's at, that he's not suffering. But we miss him too," his father said.

"None of us are promised tomorrow, even the most healthy of us. When you see a kid like Alex, you never take life for granted when you wake up in the morning and see him, waking up thankful," Ryan said.

At his funeral, bouquets of 65 roses draped Alex's casket several times over.